Green Waste Management

Food for Fuel – The Digestion of Food Waste into Renewable Energy

Every year the EU creates almost 90 million tonnes of food waste, 15 million tonnes of which is produced by the UK – states the latest report from the House of Lords European Union Committee.

The committee is urging supermarkets to end deals such as BOGOF (buy one get one free) amid concerns that at least half of food purchased in this way will end up as waste and be headed towards a landfill site. Here food waste begins producing carbon dioxide which is released into the atmosphere to a damaging effect.

However, there is an alternative. Through a process called Anaerobic Digestion food waste doesn’t need to sit in a landfill site, instead it can be turned into either Renewable Energy or Biofertiliser.

So how does it work? Anaerobic Digestion is made up of four stages…
Hydrolysis – large molecules such as carbohydrates, proteins and fats are broken down into simple sugars, amino acids and lipids.
Acidogenesis – bacteria then converts these into short-chained organic acid molecules called Volatile Fatty Acids.
Acetogenesis – the Volatile Fatty Acids are converted into Acetic Acid by bacteria.
Methanogenesis – methane forming bacteria uses the Acetic Acid to make methane.

…for which there are two outcomes:
Biogas – consisting of large amounts of methane, this gas can be used to generate renewable energy and heat. This means a reduced need for fossil fuel use, and also a reduction in the carbon dioxide produced and its release into the atmosphere.
Digestate – this leftover product is full of nutrients, which, after being cleared of pathogens through the process of pasteurization, is perfect for use as a fertiliser.

Landfill is not a long term waste solution – for food waste and other non recyclable waste.

At Rabbit Group we use an energy from waste plant that burns non-recyclable materials to generate super–heated steam. The steam is used to drive high-pressure turbines which are then used to drive a generator to produce up to five megawatts of green electricity.

To find out more about our near-zero landfill waste service at Rabbit group please call 01903 762020.